From What I've seen so far:
USA - availability in Economy not an issue. Business/First shows availability on Etihad Guest but AA agents unable to see it until ~30 days before departure. Knit-in seems to have had an outlier experience of being able to book AUH-LAX Business > 30 days out
Europe - AUH -Europe seems to have no issues in general except AUH-LHR which has
reported similar problems as the USA routes
Asia - AUH-Asia routes seem to be unaffected
Australia AUH-SYD seems to be unaffected
ROW - Not sure